Systems and methods for detection of session tampering and fraud prevention

ABSTRACT

The invention provides methods and apparatus for detecting when an online session is compromised. A plurality of device fingerprints may be collected from a user computer that is associated with a designated Session ID. A server may include pages that are delivered to a user for viewing in a browser at which time device fingerprints and Session ID information are collected. By collecting device fingerprints and session information at several locations among the pages delivered by the server throughout an online session, and not only one time or at log-in, a comparison between the fingerprints in association with a Session ID can identify the likelihood of session tampering and man-in-the middle attacks.

This application is a continuation application of U.S. patentapplication Ser. No. 11/694,882, filed on May 30, 2007, which claims thebenefit of priority to U.S. Provisional Patent Application Ser. No.60/744,107, filed on Mar. 31, 2006, which are incorporated by referenceherein in their entirety.

FIELD OF INVENTION

The invention relates to systems and methods for detecting various formsof session tampering and attempted fraud. More particularly, theinvention herein relates to systems and methodologies that identifysession hijacking and man-in-the-middle attacks during onlinetransactions with financial institutions and e-commerce transactions.

BACKGROUND

Most online transactions involving the transmission of sensitive orconfidential information require a high degree of certainty as to theidentity of the parties involved. It is well known that members of thepublic access the Internet for the purpose of conducting financialtransactions, online banking and purchasing of merchandise. Thesecommercial systems suffer from a common disadvantage in that they relyon the transmission of sensitive information over unsecured networkroutes and lines during each transaction. While these systems often relyon encryption, password protection and other security options that areconsidered relatively safe, there remains significant risk of fraud,identify theft and misappropriation of information.

The Internet can be described generally as a wide area network ofcomputers or devices that can be remotely located worldwide. Thecomputers or devices are linked by a variety of communication linksincluding telephone lines, cable television lines, satellite link-ups,wireless networks and other telecommunication connections. Internetservice providers (ISPs) provide their subscribers or end users with alink to the main backbone of the Internet. The computers and devices canconnect to the Internet and are assigned IP addresses to uniquelyidentify them and set them apart. These computer or device IP addressesmay be static or change (dynamic) during each Internet session. Each(user) session may involve some level of activity by a computer with anIP address on which a user spends time at a Web site. The number of usersessions on a site is often used in measuring the amount of traffic at aWeb site. A site administrator usually determines the time frame of auser session between logging in and out, e.g., 10 minutes, before anonline session is terminated or timed-out due to user inactivity.However if the visitor performs some level of activity within selectedtime period, this can still be considered one or the same user sessionand any transactions conducted within that time frame would beconsidered part of a single session. When a user returns to the site tobegin a log-in procedure, or after an allotted time period has expired,this would be considered another user session.

According to many marketing surveys, there is a relatively highpercentage of companies and users who refrain from purchasingmerchandise and conducting e-commerce over the Internet. There remains apersistent fear that credit card, account and other personal informationwill be intercepted online by a third party computer hacker and usedillegally despite ongoing security efforts. This comes at great expensefor users who become victims of identity theft and fraud. At the sametime, online vendors and financial institutions are subject toadditional risks in the course of transactions subject to illegalactivity such as session tampering and session hijacking Considering thenumerous types of incidents that threaten security of enterprise systemsand networks, attackers remain capable of modifying and manipulating ortaking over online sessions to commit fraud and theft.

There is a need for online solutions that detect session manipulation ortampering so that fraud and the misappropriation or misuse ofconfidential information can be avoided.

SUMMARY OF THE INVENTION

The invention provides methods and systems related to the detection ofsession tampering and/or hijacking that can be used in an effort toprevent fraud. Various aspects of the invention can be appreciatedindividually or collectively to provide solutions against sessiontampering and/or hijacking

An aspect of the invention provides methods and systems that collectmultiple computer or device “fingerprints” during online visits to sitesfor banks, financial institutions or other companies that conducttransactions over the Internet. During the course of an online session,a Session Identifier (Session ID) can be assigned to facilitate theexchange of data between computers or devices (server/client). When auser accesses or visits an online account or site using a personalcomputer (PC) or any device connected to the Internet over HTTPprotocol, a PC or device fingerprint corresponding to that computer ordevice and the relevant Session ID may be collected in accordance withthis aspect of the invention.

A preferable embodiment of the invention may incorporate one or moresteps of collecting computer or device fingerprints and Session IDs atvarious instances throughout an online session. For example, suchinformation may be collected when a user navigates to a log-in page, apage that concludes a transaction or HTML pages from a Web site that arecommon for online banking applications such as setting up new payees,changes of address (e-mail or street), and authorizing the wiring ortransfer of money. By collecting fingerprints and/or Session IDinformation at several site locations or instances throughout a session,and by tracking the assigned Session ID for that particular session,incidents of session tampering or session hijacking can be detected sothat appropriate responses may be conducted during the online session orpost-session.

In another embodiment of the invention, methods of detecting sessiontampering are also provided that involve analysis of collected devicefingerprints during different time intervals of an online session and/orat different portions of a web site being viewed. A preferableembodiment of the invention includes the analysis and comparison of PCfingerprints corresponding to a user device containing a relevantSession ID and other identifying information associated with the device.

Another aspect of the invention provides systems and methods forimplementing secure transactions including but not limited to onlinepurchases over the Internet. These solutions allow network or Internetusers to more securely perform online transactions with other partiessuch as banking and financial institutions, vendors of merchandiseand/or services or other transactions made over the Internet or acomputer network. The occurrence of incidents involving electronicinterception or session tampering or hijacking can be detected to alertcompanies who can thereby initiate responsive actions to prevent fraud,identify or credit card theft and financial loss.

Other goals and advantages of the invention will be further appreciatedand understood when considered in conjunction with the followingdescription and accompanying drawings. While the following descriptionmay contain specific details describing particular embodiments of theinvention, this should not be construed as limitations to the scope ofthe invention but rather as an exemplification of preferableembodiments. For each aspect of the invention, many variations arepossible as known to those of ordinary skill in the art. A variety ofchanges and modifications can be made within the scope of the inventionwithout departing from the spirit thereof.

Incorporation by Reference

All publications and patent applications mentioned in this specificationare herein incorporated by reference to the same extent as if eachindividual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The illustrations included within this specification describe many ofthe advantages and features of the invention. It shall be understoodthat similar reference numerals and characters noted within theillustrations herein may designate the same or like features of theinvention. The illustrations and features depicted herein are notnecessarily drawn to scale.

FIG. 1 illustrates an embodiment of the invention that detects sessiontampering by comparing a series of computer fingerprints capturedthroughout an online session with a selected Session ID.

FIG. 2 describes the comparison of multiple device fingerprints taken atdifferent times during an online session.

FIG. 3 is a table of fingerprint information corresponding to multiplesessions each identified by Session IDs.

DETAILED DESCRIPTION OF THE INVENTION

The invention provides methods and apparatus for detecting sessiontampering and hijacking that can be applied to fraud prevention. Variousaspects of the invention described herein may be applied to any of theparticular applications set forth below. The invention may be applied asa standalone tool or as part of an integrated software solution againstonline fraud, identify theft and Internet security. The invention can beoptionally integrated into existing business processes seamlessly andtransparent to a user or an attacker (hacker). It shall be understoodthat different aspects of the invention can be appreciated individually,collectively or in combination with each other

FIG. 1 is an illustration that describes a preferable embodiment of theinvention that can detect session tampering or session hijacking At thebeginning of an online session, a unique Session ID (#12345678) can begenerated or assigned by a financial institution or other companyconducting a transaction with a client or user. A Session Identifier(Session ID) may be described as a value or number generated by a serverthat identifies a particular session with a user. From the beginning tothe end of the session, the same Session ID is relied upon to correctlydirect the flow of information (data packets) between host computers, ora client and a server. A Session ID may also be described as a uniquenumber that a Web site server assigns a specific user for the durationof a user visit or session. The Session ID can be stored as a cookie,form field, or URL (Uniform Resource Locator).

Some Web servers generate Session IDs by simply incrementing staticnumbers. However, most servers use a variety of algorithms that involvemore complex methods, such as factoring in the date and time of thevisit, an IP address and other variables. In general, every time anInternet user visits a specific Web site, a new Session ID is assigned.Closing a Web browser and then reopening and visiting the site againusing the same browser may generate a new Session ID. However, the sameSession ID is sometimes maintained as long as the browser is open, evenif the user leaves the site in question and returns. In some cases, Webservers terminate a session after a few minutes of inactivity and at alater time assign a new Session ID. If a Web browser is left active whenvisiting a site but nothing is entered for a predetermined time, e.g.,15 minutes, an existing Session ID can be discarded. When browsingcontinues later even at the same site, the user will be typically givenanother Session ID automatically. The use of Session IDs alone in theirconventional form does not offer secure Web browsing.

Session IDs can be stolen using a variety of techniques: sniffingnetwork traffic, using trojans on client PCs, using the HTTP referrerheader where the identifier is stored in the query string parameters,and/or using script injectors such as cross-site scripting attacks wherea malicious script is executed that redirects information intended for alegitimate user to the hacker instead. In addition, a Web browser mayunknowingly send a URL containing a Session ID to an attacker. Hackerscan also acquire Session IDs in other various ways including sessionprediction, stealing or brute force. Afterwards they can modify theexchange of information or do something else during an already existingsession in what can be referred to as session tampering, or they canmasquerade or pose as authorized users in forms of attacks that may bereferred to as session hijacking An increasingly more common kind ofattack today is known as a man-in-the middle (MITM) attack. The attackercan observe the communication (e.g., by sniffing packets) betweendevices and collect and exploit the data that is transmitted.

Various aspects of the invention can be applied to guard against sessiontampering or hijacking during an exchange between different kinds ofcomputers or user devices. Based on a comparison of a Session IDrelative to a plurality of device fingerprints taken during a session,an authorized user may be distinguished from an attacker. Wheninformation is exchanged with an unauthorized device used by theattacker during an existing online session, it may be detectable inaccordance with the concepts of the invention. It should be understoodthat reference to a client, device or personal computer (PC) hereinincludes any telecommunications device equipped with a browser whichallows a user to access and interface with remote servers, particularlyservers at Web sites on the Internet. These devices include but are notlimited to cellular telephones, wireless handsets and telephones,personal digital assistants, palmtop/laptop or notebook computers anddesktop PCs. It should also be recognized that the illustrated Web siteserver may include or be connected to a plurality of servers for aprovider.

As shown in FIG. 1, a user client may be assigned an IP address(10.150.80.60) that may serve as a computer fingerprint by itself or itcan be combined with other user or computer based parameters. Thisfingerprint can be uniquely distinguished from that of another deviceused by a hacker which is assigned a different IP address(10.200.40.30). An IP address may be generally described as anidentifier for a computer or device on a TCP/IP network. Networks usingthe TCP/IP protocol are able to route messages based on the IP addressof a destination. The format of an IP address is a 32-bit numericaddress written as four numbers separated by periods. Each number can bezero to 255. For example, 1.150.30.220 could be an IP address. Within anisolated or private network, it may be possible to assign IP addressesat random as long as they are unique. However, connecting a privatenetwork to the Internet requires using registered IP addresses (calledInternet addresses) to avoid duplicates. The concepts of this inventionmay be combined with other systems and methods that utilize computer orPC fingerprints (PCPrints) such as those described in US 2006/0010072(Ser. No. 10/791,439), which is incorporated by reference herein in itsentirety. Another preferable embodiment of the invention may utilize adevice fingerprint that is composed of one or more relatively uniquecharacteristics attributed to the physical device itself. For example, acomputer fingerprint may relate to a time based characteristic of theinternal clock with regard to another reference clock (timedifferential) or by itself (clock skew). These and other temporalcharacteristics of a device based on computer clocks can providecomputer fingerprints in accordance with then invention by themselves orthey can be combined with other distinguishing characteristics of acomputing device.

During online sessions where the security of transmission between aclient/server is compromised, an attacker hijacks or tampers with analready established session from another PC or device that would exhibita different fingerprint. The established session between a user clientand a Web server usually has an associated Session ID already assigned.The Session ID would include a piece of generated data to be used innetwork communications often over HTTP to identify a session or a seriesof related message exchanges. Session IDs often become necessary incases where the communications infrastructure between computers uses astateless protocol such as HTTP. For example, concepts of the inventioncan be applied to provide an e-commerce solution to detection intrusionby a hacker or thief. A Buyer who visits a Seller Web site may want topurchase a number of articles during a visit and place them during theinterim in a virtual shopping cart. The Buyer can then finalize shoppingby going to the site checkout page to effect payment. This typicallyinvolves an ongoing communication where a plurality of Web pages isrequested by the client, and they are sent back by the server in turn.In such a situation, it is often important to keep track of the currentstate of the shopper cart, and a Session ID is one of the pieces ofinformation used to achieve that goal. Once the Buyer finalizes an orderor completes a certain activity, the Session ID may no longer be validor and another session would be initiated with a new Session ID in orderto purchase additional items. As described elsewhere herein, a pluralityof user device fingerprints may be collected and compared to respectiveSession IDs with respect to online ordering and purchasing in order todetect session tampering or hijacking

In a preferable embodiment of the invention, as illustrated in FIG. 1, aSession ID can be generated when a visitor or customer user visits anonline financial or banking institution Web site. When logging-on to thesite from a home page (Page 1), a new session may commence and theassociated Session ID may be generated and stored by various ways asdescribed elsewhere herein such as a cookie by a Web browserapplication. The browser may transparently include the cookie data inall subsequent page requests to a server within the financialinstitution system, thus allowing it to identify the session and sendback pages to the user that may include such financial or personal dataas requested. Unlike user IDs (e.g., personal user names or numbers),Session IDs are typically short-lived since they expire after a presettime of inactivity which may be minutes or hours (timed-out) or maybecome invalid after a certain goal or activity has been met oraccomplished (log-out or logoff).

Some preferable embodiments of the invention can be employed to defendagainst session hijacking by collecting PC fingerprints and Session IDinformation at multiple points of time or selected time intervals duringan online banking session. Session hijacking has been described as theact of taking control of a user session after successfully obtaining orgenerating an authentication Session ID. Often times session hijackinginvolves an attacker using Session IDs captured by techniques involvingbrute force or reverse-engineering in order to seize control of abanking session and other Web application sessions while that session isstill in progress.

A Session ID is often an identification string that is usually composedof a long, random, alpha-numeric string that is transmitted between hostdevices such as a client and a server. Session IDs are commonly storedin cookies, URLs and hidden fields of Web pages. A URL containing aSession ID might resemble something such like the following:http://www.123somesite.com/view/7AD30725122120803. In an HTML page, aSession ID may be stored as a hidden field and resemble something likethe following: <input type=“hidden” name=“sessionID” value=“54321abcd”>.Alternatively, cookies can include Session ID information and can be setto expire (or be deleted) upon the closing of a Web browser. These aretermed “session cookies” or “non-persistent” cookies typically. Cookiesthat last beyond a user's session are termed “persistent” cookies.Persistent cookies are usually stored in memory on a computer harddrive.

There are other known shortcomings or problems associated with employingSession IDs besides how they can be readily located by hackers. Manypopular Web sites use algorithms based on easily predictable variables,such as time or IP address, in order to generate the Session IDs,causing their Session IDs to be predictable. If encryption is not used(typically SSL), Session IDs are transmitted in a clear and susceptibleform that is susceptible to eavesdropping and session hijacking Insession hijacking attacks, an attacker usually takes over an alreadyexisting session that is underway. This may occur entirely unnoticed bythe authorized user who may still believe an online session is ongoing.As described elsewhere herein, a client and server communication usuallytakes place across a network using IP-based communication methods. Anattacker may use a computer and hacking software or tools to gain accessto a connection between a legitimate client and Web server on theInternet, for example. The attacker can then inspect and capture traffic(packets) going over the network during an online session. By beatingthe client in replying back to the Web server with seemingly legitimatemessages, the session may thus continue but with the attacking hostcomputer. Accordingly, the session with the legitimate client can bedropped and the attacker can practically do anything that the legitimateclient could accomplish.

Accordingly, this aspect of the invention presents comparative evidenceof session hijacking when the same Session ID is used by differentcomputers or devices that exhibit different fingerprints. A one-to-manyrelationship as between a Session ID and multiple device fingerprintswould suggest that the online session was compromised so remedial actionshould be taken or required to prevent fraud or minimize risk of loss.In a preferable embodiment of the invention, a one-to-many relationshipas between a Session ID and multiple IP addresses could be used tosignal or identify the occurrence of session hijacking The step ofauthentication can be performed numerous times during an online sessionrather than just at log-in to confirm user identities based on theirdevice fingerprints for a corresponding Session ID in progress. Itshould be understood that device fingerprints may include an IP addresscomponent alone or with a combination of other parameters orcharacteristics of the device.

In another embodiment of the invention, methods of detecting sessiontampering are also provided. Attacks involving session tamperingtypically involve an attacker (or a computer program that runs on behalfof an attacker) doing something that allows the revelation ormodification of the characteristics to an already established session.

Methods provided herein to detect session tampering may include aninitial step of placing a plurality of fingerprint collectors inpreselected or strategic locations on a Web site. A fingerprintcollector may be described as a computer program residing in the memoryof computer or server that is designed to extract device fingerprintinformation from the data or information exchanged between a (Web)server in order to identify a user device characteristic including butnot limited to IP address information (see FIG. 1—Bank Server).

The Web site may be designed with a group of pages (HTML pages) thatcontain any number of hyperlinks to each other and made available onlineby an individual, company, educational institution, government, ororganization. For example, a financial institution may place fingerprintcollectors at a log-in page (Page 1) where a customer use accesses abank account. Other pages (Page 2) may include a fingerprint collectorsuch as a portion of a Web site designed to facilitate electronicchecking transactions or activity such as pages to “Add a New Payee” orto “Change E-mail/Street address or User Profile Information” or to“Wire Funds” or to “Make a Payment.”

As with other embodiments of the invention herein, another stepaccording to this methodology may include placement of a sessioncollector for collecting Session ID data on each page, which is providedby an established default mechanism for most Web sites to manage andidentify user sessions. A session collector may be described as acomputer program residing in the memory of computer or server that isdesigned to extract device Session ID information from the data orinformation exchanged between a (Web) server in order to identify aparticular online session (see FIG. 1—Bank Server). While a comparisonbetween a plurality of fingerprints for a particular Session ID may beaccomplished real-time during a session, a preferable embodiment of theinvention includes a subsequent step of comparing fingerprints followingtermination of a session (post-session) after log-out (Page N). All ofthe collected fingerprints from a session can be compared with a SessionID for a particular session. This comparison can detect when or if thefingerprints of a computer or device used during the session are not allidentical. When the fingerprints collected at different pages and timesthroughout a session are not the same for a selected Session ID, thismay suggest that session hijacking and/or session tampering occurredthrough some unauthorized intervention. It should be understood thatalternative aspects of the invention include modification and creationof corresponding algorithms to perform any or all of the precedingsteps.

Another aspect of the invention provides systems and methods forimplementing secure transactions including but not limited to onlinepurchases over the Internet. During preselected time intervals or pagesat a Web site, a plurality of computer fingerprints may be collectedthroughout the session for the computer on which a consumer conducts apurchase online by using and entering credit card information. Inaddition, the computer fingerprints can be collected and compared to aSession ID number assigned to the session by an online merchant. When aselected fingerprint is determined to be different from the otherscollected during the session, the merchant will be able to suspectpossible session tampering or hijacking By collecting fingerprints andSession ID information in several locations of the site in accordancewith this aspect of the invention, online retailers and others who areexposed to Internet fraud can identify when a session has been tamperedwith or hijacked by another device (hacker computer) that is using thesame Session ID.

As shown in FIG. 2, one or more fingerprints may be compared todetermine whether they match or not during an online session. For thatparticular online session, a persistent Session ID should be assignedand maintained for a particular user device. The user device shouldexhibit the same fingerprint throughout the session to suggest that nocommunications exchanged with a Web server came from or were redirectedto another device. A first fingerprint (Fingerprint 1) can be comparedagainst a second fingerprint (Fingerprint 2) in a preferable embodimentof the invention. One, two or more fingerprints may be collected withdevice fingerprint collectors as described elsewhere herein during anyselected time interval of a session, or at any selected Web page thatmay be requested and viewed by a user through a browser. Session IDinformation may be also collected at substantially the same time. Forexample, an authentication server may be configured to extract the IPaddress from the information exchanged between a Web server and a userdevice. The IP address alone may form the device fingerprint or otherparameters or user device characteristics may be included too such as aBrowser ID. If the first fingerprint matches the second fingerprint withrespect to the same Session ID, then the user may be allowed to proceedto another Web page or portion of a site.

Furthermore, for online banking applications, the first fingerprint maybe taken while the user is logging-on from a home page. A Session ID canbe then established for that session. Before allowing the user toperform online banking functions or activity including but not limitedto withdrawing or transferring funds or changing passwords, the secondfingerprint may be collected along with its corresponding Session IDinformation. Unlike conventional systems, this additional authenticationstep is performed again so that the comparison between fingerprints canbe performed for that particular session relative to the same SessionID. When the fingerprints do not match, then the activity requested maybe immediately denied and communicated to the user. For otherapplications of the invention, the transaction may be flagged forfurther review later by the financial institution. It may not bepreferable often times to reveal to attackers at what point in timeduring a session was fraud suspected.

Another preferable embodiment of the invention provides post-sessioncomparison of user or device fingerprints and Session IDs. This analysisallows the merchant to reject a transaction or to at least flag anincident so that further investigation can be conducted. For example,many financial institutions (e.g., Bank of America) build-in lag time ordelay as to when financial activity such as electronic checking can becompleted by a customer payor and mailed to a payee. An online customermay be advised of status such as the transaction is “pending” or “inprogress” or “scheduled.” During this time, in addition to other desiredprocedural checks implemented by the financial institution, a series ofcustomer transactions reports can be analyzed for possible fraud.

FIG. 3 illustrates another embodiment of the invention that providesbackend solutions to detect and prevent fraud. A server may residedwithin the network of a financial institution and have a database memoryfor storing customer transactions with corresponding sessioninformation. The session information may include a plurality of SessionIDs (SID1, SID2 etc.) for one or more customers requesting numeroustransactions. Each transaction may have a Session ID and a plurality ofuser fingerprints (FP1, FP2 etc.) obtained or collected at differenttimes during the session or at different locations/pages of the bank Website. As with other embodiments of the invention, it shall be understoodthat the number of user fingerprints collected may be varied. Forcertain kinds of transactions, accounts or instances where the levels ofsuspected fraud are unusually high, it may be preferable to collectrelatively more fingerprints throughout an online session. The sessioninformation may include the times (t1, t2, etc.) as to when fingerprintsare collected and/or the locations (Web pages) where fingerprints areobtained (P1, P2 etc.). For preferable embodiments of the invention, aperson (fraud case analyst) can manually inspect and review the sessioninformation and customer transaction reports, or a computer program canbe selected to compare user fingerprints collected corresponding to aparticular Session ID in order to assess the likelihood of fraud.Accordingly, these fraud detection solutions can be relatively invisibleto an attacker (hacker) and provide more secure user transactions withparties such as banking and financial institutions, vendors ofmerchandise and/or services or other transactions made over the Internetor a computer network. The occurrence of incidents involving electronicinterception or session tampering or hijacking can be detected to alertcompanies who can thereby initiate responsive actions to prevent fraudand financial loss.

The invention herein provides methods and systems for fraud preventionand security relating to online sessions with users on a network or theInternet. It shall be understood that principles of the invention can beapplied and modified for application with other fraud prevention andsession monitoring systems and methods such as those described inpublished U.S. patent applications US 2002/0073046 (Ser. No. 09/875,795)and US 2004/0254890 (Ser. No. 10/444,506), which are each incorporatedby reference herein in their entirety. Any of the aforementionedembodiments of the invention can be also integrated into existingbusiness processes and state-of-the art security systems. For example,the invention may be applied to authentication systems that incorporatestatic (persistent) passwords that remain the same in between sessionsand log-ins. Or, alternatively, various aspects of the invention can beapplied to systems that provide a one-time password (OTP) that changesfor each online session. The use of an OTP makes it more difficultusually to gain unauthorized access to restricted resources or onlinesessions. An OTP may be essentially a series of numbers or othercharacters generated by a mathematical algorithm (soft token) and/ordisplayed on a physical device (hard token) that is synchronized with anauthentication server. Even with relatively secure sessions protected byOTP authentication, session tampering and/or hijacking is possible.Accordingly, multiple computer or device fingerprints can be collectedas described above during multiple points or places during an onlinesession authenticated with an OTP token so that a comparison can be maderelative to particular Session ID.

It should be understood from the foregoing that, while particularimplementations have been illustrated and described, variousmodifications can be made thereto and are contemplated herein. It isalso not intended that the invention be limited by the specific examplesprovided within the specification. While the invention has beendescribed with reference to the aforementioned specification, thedescriptions and illustrations of the preferable embodiments herein arenot meant to be construed in a limiting sense. Furthermore, it shall beunderstood that all aspects of the invention are not limited to thespecific depictions, configurations or relative proportions set forthherein which depend upon a variety of conditions and variables. Variousmodifications in form and detail of the embodiments of the inventionwill be apparent to a person skilled in the art. It is thereforecontemplated that the invention shall also cover any such modifications,variations and equivalents.

What is claimed is:
 1. A method for detecting session tampering, themethod comprising: establishing a Session ID for an online sessionbetween a first computer and a second computer over a network, whereinthe online session is initiated at a log-in page and terminated at alog-out page; instructing the first computer to collect at least twodevice fingerprints during the online session from the second computerfor the corresponding Session ID, wherein the two device fingerprintsare collected during the online session from at least two differentpre-selected pages displaying different content that are configured fora session tampering comparison; and comparing, after termination of theonline session at the log-out page, the two device fingerprints takenduring the online session from the at least two different pre-selectedpages, and if the two device fingerprints are not identical, detectingsession tampering and providing an alert.
 2. The method as recited inclaim 1 wherein the at least two device fingerprints include IP addressinformation for the second computer.
 3. The method as recited in claim 1further comprising the step of collecting Session ID informationcorresponding to the two device fingerprints at the same times ascollecting the two device fingerprints.
 4. The method as recited inclaim 1 wherein the network is the Internet.
 5. The method as recited inclaim 1 wherein the first and second computers is a user client and aserver for an online merchant respectively.
 6. A method of detectingsession tampering, the method comprising: establishing a Session ID foran online session between a user device and a Web server; instructingthe Web server to collect at least two fingerprints, each of the twofingerprints including a time differential between an internal clock ofthe user device and another reference clock, during at least twodifferent time intervals from the user device for the correspondingSession ID, wherein the two fingerprints are collected during the onlinesession from at least two different pre-selected locations displayingdifferent content that are configured for a session tamperingcomparison; and comparing the two fingerprints taken during the at leasttwo different time intervals from the at least two differentpre-selected locations to determine whether they are identical in orderto detect session tampering.
 7. The method as recited in claim 6 whereinthe two different time intervals coincide with the viewing of twodifferent pages served from the Web server to the user device.
 8. Themethod as recited in claim 6 wherein the two different pages are HTMLpages, and wherein one page is a log-in page and the second page relatesto activity calling for additional authentication.
 9. The method asrecited in claim 8 wherein the Web server is operated by a financialinstitution, and second page relates to authorizing the transfer ofmonetary funds.
 10. The method as recited in claim 8 wherein the Webserver is operated by a Internet retailer, and the second page relatesto authorizing a charge to be made for the purchase of merchandise usingcredit card information to be entered from the user device.
 11. Anon-transitory computer readable medium containing program instructionsfor carrying out a method of detecting session tampering, said methodcomprising: establishing a Session ID for an online session between auser device and a Web server; instructing the Web server to collect atleast two fingerprints, each of the two fingerprints including a timedifferential between an internal clock of the user device and anotherreference clock, during at least two different time intervals from theuser device for the corresponding Session ID, wherein the twofingerprints are collected during the online session from at least twodifferent pre-selected locations displaying different content that areconfigured for a session tampering comparison; and comparing the twofingerprints taken during the at least two different time intervals fromthe at least two different pre-selected locations to determine whetherthey are identical in order to detect session tampering.
 12. Anon-transitory computer system loaded with machine readable instructionsfor carrying out a method for detecting session tampering, said methodcomprising: establishing a Session ID for an online session between afirst computer and a second computer over a network, wherein the onlinesession is initiated at a log-in page and terminated at a log-out page;instructing the first computer to collect at least two devicefingerprints during the online session from the second computer for thecorresponding Session ID, wherein the two device fingerprints arecollected during the online session from at least two differentpre-selected pages displaying different content that are configured fora session tampering comparison; and comparing, after termination of theonline session at the log-out page, the two device fingerprints takenduring the online session from the at least two different pre-selectedpages, and if the two device fingerprints are not identical, detectingsession tampering and providing an alert.
 13. A network security systemfor a financial institution that detects when an online session iscompromised comprising: a server within the financial institutionnetwork for establishing an online session between a customer computerthat is designated with a Session ID; a fingerprint collector within thefinancial institution network for collecting device fingerprints atpredetermined intervals during the online session from the customercomputer, wherein the device fingerprints are collected during theonline session from at least two different pre-selected pages displayingdifferent content that are configured for a session tamperingcomparison; a session collector within the financial institution networkfor collecting Session ID information at predetermined intervals duringthe online session from the customer computer, and a memory for storinginformation collected from the fingerprint collector including the pageswhere the device fingerprints are obtained and the session collector inorder to enable a comparison between the device fingerprints collectedfrom the at least two different pre-selected pages and the Session IDinformation that suggests that an online session is compromised if thedevice fingerprints are not identical.
 14. The network security systemas recited in claim 13, wherein the online session is authenticated witha one-time password (OTP).
 15. The network security system as recited inclaim 13, wherein the predetermined intervals during the online sessionare defined when the customer navigates to a log-in page and anotherpage calling for further authentication provided by the server of thefinancial institution network.